The present invention relates to a corner bracket of nearly triangular form to be installed mainly at upper end edge corner of a sashless-type automotive side door.
Corner brackets of the above-mentioned type are known from Japanese patent application Nos. 12735/1985, 234046/1985 and 234047/1985. When a door mirror (an accessory to be attached) is attached to a sashless door, for example, a door mirror attaching body is used where the door mirror attaching body comprises a mirror attaching member (attaching member for attaching an accessory to be attached) 9 of nearly triangular form, having an outward size sufficient to fill an angle space formed between a door belt line 5 while the door is closed (referred to herein as the door closed state), and a front pillar (slant pillar) 7 disposed on the upper side of the door belt line 5, and an attaching foot member 11 extending downward from the mirror attaching member 9 and fixed to the sashless door (door body) 1 as shown in FIG. 1.
The mirror attaching member 9 as shown in FIGS. 2 and 3 comprises a glass enclosing groove 13 with cross-section of U-like form having its bottom portion contacting the an edge of the front pillar 7, a door glass run installed on an opening end edge of the glass enclosing groove 13 in opposition to the angle part and composed of a pair of lip strips 15, 15 which converge towards their outer, free ends, and mirror attaching holes 17 (three in number in this example) crossing the glass enclosing groove 13.
The mirror attaching member 9 is molded in a process in which a U-like insert 19 of metal sheel extending integrally from the attaching foot member 11 is coated with a high molecular weight elastic material such as PVC, PVC/NBR polyblend, EPDM or the like by means of transfer, injection molding or the like. More specifically, as shown in FIG. 4, the outside surfaces of the mirror attaching member 9 is formed by a stationary mold 21 and a movable mold 23, and the glass enclosing groove 13 is formed by a core 27 and the mirror attaching hole 17 is formed by a column portion 25 projecting from one of the stationary mold 21 or the movable mold 23, from the movable mold 23 in this example. The column portion 25 is fitted through a hole 29 formed on the core 27. The column portion is preferably formed as a circular column corresponding to the shape of the attaching hole 17, but the column may be square in transverse cross-sectional shape.
During the molding, usually, since a cylindrical gap 31 is formed between the column portion 25 and the through hole 29, a cylindrical flash 33 is produced in the molding product. The cylindrical flash 33 is cut by movement of the core 27 in the white arrow direction during the mold releasing operation. However, since the thickness of the cylindrical flash 33 is nearly constant in the axial direction, the cutting position is not fixed. Consequently, when an attaching boss 34 of the mirror body is inserted from one end of the attaching hole 17 and locked by a screw 37 as shown in FIG. 5, a remaining portion of the flash 33 may become trapped in between the internally screw-threaded fitting 35a of the attaching boss 35 and the screw 37 as shown in FIG. 5 so that performing the task of assembling becomes impossible. Consequently, usually, a step of removing the cylindrical flash is required to be performed after the molding has been completed. Since the cylindrical flash is within the glass enclosing groove, the removing work is troublesome, resulting in an increase in the number of process steps required.
When the above-mentioned door mirror bracket is viewed from the inside of the automobile, the mirror attaching hole 17 and the insert 19 are exposed as shown in FIG. 2. Furthermore, rainwater or wind resistance-generated sound may infiltrate the automobile from outside through the attaching hole 17. Consequently, a blind plate 39 having similar shape to that of the mirror attaching member 9 must be detachably installed as shown in dash--and--dot line of FIG. 2.
In this case, a locking foot can be formed on the rear surface of the blind plate 39 and a locking hole can be formed corresponding to the insert of the mirror attaching member 9 so that the locking foot is engaged with the locking hole and by this means the blind plate 39 is attached to the mirror attaching member 9.
In order to overcome such problems with the prior art construction, the present inventors have devised a modified structure, shown in FIG. 6, in which the locking foot is projected in the glass enclosing groove 13 and therefore does not interfere with the door glass run G and nor cause an interference problem while being molded.
A locking foot 39a with top end swollen is formed on the rear surface of the blind plate 39, and a cylindrical boss 43 having a bottomed locking hole 41 with an enlarged diameter at its base and a locking step 41a formed corresponding to the locking foot 39a is formed on the inside wall (relative to the automobile) 51 of the mirror attaching member 9.
Molding of the mirror attaching member 9 having the cylindrical boss 43 may be performed, in order to suppress use of the slide core to the maximum extent possible, as shown in FIG. 7 where the automobile inside wall-forming surface 45 is provided with a boss outer circumference-forming surface 46, a boss end forming surface 47 and a locking hole-forming column portion 48 in a metal mold similar to that of FIG. 2. In this case, during performance of the step of mold releasing, the outer circumference of the cylindrical boss 43 is restricted and the locking hole-forming column portion 48 is forcedly drawn out of the bottomed locking hole 41 of the cylindrical boss 43, and undercut amount of the locking hole 41, i.e., width X of the locking step 41a is taken large from the viewpoint of locking reliability, whereby the cylindrical boss 43 may be broken and released from the mold resulting in failure of the molding.